Electric transformer.



No. 640,314. Patented Jan. 2,1900. J. W. PACKARD & H. W. WISWELL.

ELECTRIC TRANSFORMER.

(Application filed June 23, 1898.) (No Model.) 2 Sheets-Sheet l.

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No. 640,3I4. Patented lan.2, I900.

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ELECTRIC TRANSFORMER.

(A lication filed June 23, 1898.)

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UNITED STATES PATENT @EFIGE.

JAMES \V. PACKARD AND HENRY N. lVISlVELTl, OF WARREN, OlllO.

ELECTREC TRANSFQRM SPECIFICATION forming part of Letters Patent No. 640,814, dated January 2, 1900.

Application filed June 23, 1898. Serial No. 684,228. (No modclf) T0 (0% whom it may concern:

Be it known that we, JAMEs W. PACKARD and HENRY W. WIsWELL, citizens of the United States, residing at Varren, in the county of Trumbull and State of Ohio, have invented certain new and useful Improvements in Methods of Winding Electric Transformers, of which the following is a specification.

Our invention relates to improvements in methods of winding the cores of electric transformers; and it consists in the novel steps and peculiar arrangement of parts that will be hereinafter described.

While our invention may be advantageously employed in connection with cores of various styles or character, we have in the accompanying drawings illustrated one form of such device to which our improvements are particularly applicable.

In said drawings, Figure 1 is a rear view of the transformer, part of the casing being broken away to show the interior construc tion. Fig. 2 is an end view of the transformer. Fig. 3 is a plan View of the same with cover removed. Fig. 4 is a vertical section on the line 4 4 of Fig. 3, the winding being shown in full. Fig. 5 is a detail perspective view of a transformer-core. Fig. 6 is a plan view of the core shown in Fig. 5, with winding added. Fig. 7 is a perspective view of the end of one of the core-sections illustrated in Fig. 6, and Fig. 8 is a diagram illustrating our method of winding the cores.

Referring to Figs. 1 to 4, inclusive, A indicates the casing of the transformer, and a a top or cover of the casing. The casing is provided on its back with two pairs of hooks 1, into which fit cross-bars 2 of a frame upon which the transformer may be hung when it is desired to support it upon a pole. To the ends of the bars 2 are attached vertical bars 3, which have rectangular hooks at at their upper ends adapted to fit over a cross-arm upon a pole. At each end of the casing, near the top, is a depending hook, under which a rope may be passed for the purpose of hoisting the transformer. The hooks 5 are on projecting brackets 6, which are used as supports for the bolts 7, by means of which the covers are fastened. The bolts pass through holes in the covers and corresponding holes in the brackets 6.

The transformer-core B is a rectangular structure composed of strips or laminae which are interlocked, as will be hereinafter explained. The strips forming the core are secu rel y h eld together by metal clamps 8, which are insulated from the core by strips 9 of suitable material. The clamps 8 of the core rest upon the bottom of the casing, and the core is centered and held from lateral move ment by projections 10, extending upward from the bottom of the casing at its sides and ends. After the transformer is set into the casin g a pair of stout bars 11 are placed across the top of the casing a short distance above the transformer-core, the ends of the bars being held in recesses beneath shoulders 12, which are cast on the inner face of the casing. Tapped into the middle of each of the bars 11 is a setscrew 13, the lower end of which is arranged to bear upon the clamps 8 at the top of the core. The clampingscrews 13 therefore hold both the bars 11 and the transformer tightly in their respective positions in the casing, the bars being pressed upward and the transformer downward.

The wall 14 of the casing extends upward part way to the cover. Outside of the upper portion of this wall, at the corners of the easing, are compartments 15, which have outer walls 16, fitting the cover. In the bottoms of these compartments 15 are the insulatingbushings 17, through which the wires enter and leave the transformer. Fastened to the inside wall of the casing is a porcelain connection-board 18 for connecting the primary coils in series or multiple.

Our invention, as aforesaid, is applicable to cores of various cross sectional forms. Thus in Figs. 5, 6, and 7 we have illustrated it as applied in the construction of a core the side sections of which have a star-shaped crcsssection, as illustrated in Fig. 6. By assembling the strips properly the eight projecting corners of the star-shaped section can be brought into a circle, as illustrated in Fig. 6, which shows a coil in diagram.

Referring to Figs. 5, 6, and 7, it will be seen that the side sections of the core are 0011- structed of a number of groups of wide plates and a series of groups of narrow plates 26, arranged on each side of the wide plates. The narrow plates are preferably of the same length as the wide plates, and their inclined ends are preferably cut away at a less angle than 45 degrees, so that the plates in the end sections may be all of the same width, as shown in Fig. 5. The middle plates of the end sections have their angular ends cut on an angle that is a complement of the angle of the side plates 25, and the outer plates of the end sections also have their angular ends cut on an angle that is the complement of the angle of the side plates 26.

Our novel method of winding will be readily understood from an inspection of Fig. 8. This figure is a diagram in which only a few wires, greatly enlarged, are shown to simplify the illustration. A portion of the core is indioated at 28. Upon this core is first laid one or more sheets of insulating fabric 29. A strip of material is then wrapped about the core at one end and a few turns of wire 31 placed upon it. The outer edge of the strip 30 is then folded in over the wires 31 and secured by the next turns of wire 32. I Succeeding turns of wire 33 are then placed on the Wrapper 29 until the opposite end of the core is nearlyreached. A sheet of insulating material 34 is then placed on the first layer of wire, extending from the left end in Fig. 12 and having a projecting portion 35 to be turned in, as will be presently explained. The sheet 3a is first secured in place by the last few turns 36 of the first layer of Wire. Upon these are laid the first few turns 37 of the succeeding layer. The projecting edge As the winding accumulates additional sheets of insulating material 38 and 39 are used in the same manner as the sheet 3 1. By this method of winding we securely retain in position the turns of wire at each end of the core and prevent them from slipping, and we produce a coil having its ends entirely inclosed and insulated. After the requisite amount of wire has been wound 011 the coil we preferably place one or more sheets 40 over the outer layer of wire and bring them down over the ends of the coil. The extensions of the basesheets 29 are then folded in upon the coil and their ends are overlapped and secured, as shown at 41.

Having described our invention, what we claim, and desire to secure by Letters Patent of the United States, is-- The method of winding and insulating consisting in laying a layer of insulating material over a layer of wire prior to putting on the last turns thereof, said insulating material projecting beyond the core, then finishing the winding of the layer and beginning the succeeding layer, then folding in the projecting end of the sheet upon the body thereof to surround the end turns of wire, then confining said projecting end by succeeding turns of wire of the second layer and in like manner insulating and securing the succeeding layers, whereby the layers of winding are separated and the turns of wire at the ends of the winding are securely inclosed and held, substantially as described.

In testimony whereof we affix our signatures in presence of two witnesses.

JAMES WV. PACKARD. HENRY XV. WISWELL. Witnesses:

M. S. ANDREWS, RoBT. E. GORTON. 

